Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5427018 | Journal of Quantitative Spectroscopy and Radiative Transfer | 2017 | 8 Pages |
â¢Magnesium monohydride is an important molecule in astrophysics.â¢High resolution emission spectra of MgD radical have been analyzed.â¢The A 2Î â¯ââ¯X 2Σ+ bands of MgD with vâ²â¯=â2 and vâ²â¯=â3 were rotationally assigned.â¢Local perturbations were observed in the A 2Î and Bâ² 2Σ+ excited states of MgD.â¢Off-diagonal electronic matrix elements were determined from a deperturbation analysis.
High resolution Fourier transform emission spectra of MgD radical were analyzed, and the A 2Î â¯ââ¯X 2Σ+ bands with vâ²â¯=â2 and vâ²â¯=â3 were rotationally assigned. Several local perturbations were observed in the A 2Î and Bâ² 2Σ+ excited states of 24MgD, and a deperturbation analysis was carried out using an appropriate Hamiltonian matrix containing off-diagonal terms connecting the vibrational levels of the two states. Dunham coefficients and band constants were determined for the A 2Î and Bâ² 2Σ+ states, along with off-diagonal parameters. The equilibrium vibrational constants Ïe and Ïexe have been determined to be 1155.040(6) and 16.764(4)â¯cmâ1, respectively, for the A 2Î state, and 598.108(11) and 6.394(8)â¯cmâ1, for the Bâ² 2Σ+ state. The equilibrium Mg-D distances were found to be 1.67819(3) à and 2.59355(2) à for the A 2Î and Bâ² 2Σ+ states, respectively. RKR potential curves were constructed for the A 2Î and Bâ² 2Σ+ states, and vibrational radial overlap integrals were computed for the perturbed levels. The off-diagonal matrix elements coupling the electronic wavefunctions of the A 2Î and Bâ² 2Σ+ states were determined independently for MgD to be a+â¯=â18.9â±â0.2â¯cmâ1 and bâ=â0.694â±â0.005, in excellent agreement with those for the MgH isotopologue.
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